Regulator.



No. 708,289. Patented Sept. 2, I902.

H. B. P. WRENN. REGULATOR.

(Application filed Aug. 10, 1901.) (No Model.)

5 Sheets-Sheet I.

WITNESSES:

THE Moms PETERS co. PHOTO-LUNG" WASHINGTON. u. c.

No. 708,289. Patents ad Sept. 2, I902. H. B. P. WRENN. REGULATOR.

(Application filed Aug. 10, 1901.)

(No Model.) 5 Sheets-$heet :2.

7 Ann fin WITNESSES:

I fir WAHIIIIIIIHW Patented Sept. 2, 1902..

H. B. P. WBENN.

REG ULATOR; (Application filed Aug. 10, 1901.)

M Wm a ATTORNEY No. 708,289. Patented Sept. 2, I902. V

' H. B. P. WRENN.

REGULATOR.

(Application filed Aug. 10, 1901.)

(No Model.) 5 Sheets-Sheet 4.

ILI llllll I lH IIHH WITNESSES: I INVENTOR ATTORNEY E NORRIS PETERS co,PHUTO-LITHQ, WASHXNGTON n c H. B. P. WRENN.

REGULATOR.

(Application filed Aug. 10, 1901.)

(No Model.) 5 Sheets-Sheet 5.

INVENTOR ATTORN EY Unites dramas PATENT Finch,

HENRY B. I. VRENN, OF NEW YORK, N. Y.

REGULATOR.

SPECIFICATION forming part of Letters Patent No. 708,289, datedSeptember 2, 1902.

Application filed August 10, 1901. gerial No. 71,649. (No model.)

My invention relates to improvements in apparatus for operating dampersin furnaceofftakes, such as are employed for opening and closing suchdampers automatically, for the purpose of preventing wasteful passage ofair through the furnace and unnecessary loss of heated gases.

My improved damper-regulating apparatus is operated through variation inpressure or suction in the furnace consequent upon the opening orclosing of the furnace-door.

My invention consists in the combination, with a suitable motor foroperating a damper in the offtake of a furnace, and a controllingdevice, usually a diaphragm, operated by variation in pressure withinthe furnace produced by the opening and closing of the furnacedoor andby the opening andclosing of the damper in the furnace-offtake, of anactuating device for controlling the operation of the motor, itselfcontrolled by said controlling device or diaphragm, but deriving thepower by means of which it controls the operation of the motor from asource independent of the said controlling device or diaphragm.

My invention further consists in the use in the above combination of anenergy-storing actuating device and in storing in such actuating devicethe power required for the control of the motor through the operation ofthe motor itself.

My invention further consists in the many novel features of combination,construction, and arrangement of the parts.

In the operation of furnaces, such as the furnaces of steam-boilers, inthe ordinary manner much loss results from the inrush of air at timeswhen the furnace doors are opened, as they must be for the purpose ofadding fuel and for cleaning the fire. The air so entering is notnecessary for combustion, and its entry produces a considerable loss, asin passing up the chimney it carries with it a great quantity of heat,which is practically wasted. Moreover, the air so entering chills thefurnace and injuriously affects the boiler, if a boiler is used inconnection with the furnace, by chilling the parts of the boiler withwhich the air comes in contact, thus setting up destructive stresses.Such inrush of air can be prevented by providing in the chimney orbetween the chimney and the combustion-chamber of the furnace a damperwhich may be closed before the furnacedoors are opened and may be openedas soon as the furnace-doors are closed; but such dampers if notoperated automatically do little good, as the furnace attendants neglectto operate them. For operating such dam- .pers automatic apparatus hasbeen used, the

operation of which is caused by the variation in pressure in thecombustion-chamber of the furnace consequent upon the opening andclosing of the furnace-door and upon the opening and closing of thefurnace-damper. When the furnace-door is closed, the chimney-draftproduces a slight vacuum in the combustion-chamber. \Vhen thefurnace-door is opened, this vacuum is relieved in a measure. It isthese variations in pressure which operate the pressure'operatedcontrolling device or the diaphragm of the ap paratus above mentioned;but since the difference between atmospheric air-pressure and theair-pressure in the combustion-chamber is never very great and thevariations in pressure in the combustion-chamber relative to atmosphericpressure are smallbut very little power is available for the operationof a device controlling the opening and closing of the damper.

Heretofore attempts have been made to operate a damper in afurnace-offtake by a diaphragm exposed on one side to atmosphericpressure and upon the other side to the pressure in thecombustion-chamber of the furnace and mechanically connected with thesaid damper; but it has been found impossible to operate a damper inthis way, because the pull which may be exerted by a diaphragm ofpracticable dimensions is much too small to operate the heavy dampersthat must be employed in furnace-offtakes. Likewise the variation inpressure consequent upon the opening of the furnace-door after the draftof the furnace is fully established does not take place between the samelimits as variation in pressure consequent upon closing the furnace-doorafter the damper in the furnaceofftake has been closed or nearly closed.For example, when the furnace-door is closed and the damper in theofftake open and the draft fully established the pull upon the entirearea of the diaphragm may be equal to twenty ounces. (The amount of thispull is as sumed for the purpose of illustration. The amount in anyparticular case will depend upon the area of the diaphragm and upon thenormal draft of the furnace.) Opening of the furnace-door may reducethis pull to eighteen ounces, and such reduction in pull must cause theoperation of the apparatus and the closing of the damper in the offtake.The closing of this damper and the consequent cutting off of the draftmay reduce the pull upon the diaphragm to practically zero, and theclosing of the furnace-door (the damper in the offtake being nearlyclosed) may raise the total pull upon the diaphragm to no more than twoounces, and this increase in pull upon the diaphragm to two ounces mustbe sufficient to cause the operation of the apparatus and the opening ofthe damper in the offtake. After the damper is opened wide thefurnace-draft will be fully reestablished and the pull on the diaphragmwill increase to twenty ounces, as before. It will be seen, therefore,that the variations in pressure in the combustion-chamber, which mustsuffice to produce closing of the damper in the offtake, take place atone end of a pressure-scale, while the variations which must suffice tocause opening of the damper in the olftake take place at the other endof such pressure scale. When a diaphragm is mechanically connected to adamper, there is no provision for compensating for this differencebetween the variations in pressure which must cause the closing of thedamper and those which must cause its opening. Attempts have also beenmade to operate dampers in furnace-offtakes by employing a hydraulicmotor for operating the damper and causing-the diaphragm to operatedirectly the controlling-valve of the motor. Such apparatus has beenonly partially successful and has been in the main unreliable, becauseit has been found impossible to obtain from a diaphragm sufficient powerto operate the controlling-valve reliably. It has been found that thecontrolling-valves are apt to stick in their seats, either as the resultof corrosion, the tightness of theirstuffing-boxes, the presence ofsediment in the water, or wedging of the valve in its seat. In myimproved damper-regulating apparatus herein described I overcome thesedifficulties by interposing between the pressure-operated controllingdevice or diaphragm and the motor-controller an actuating device whichderives its power from a source independent of the pressureoperatedcontrolling device and preferably from the motor itself and whichismerely controlled by said controlling device and in turn controls theoperation of the motor-controller. The said actuating device is, in aword, a relay, by means of which the very slight power available at thediaphragm may be sufficient to effect the operation of a motorcontrollerrequiring for its reliable operation much greater power. This actuatingdevice may be a simple spring or plurality of springs or equivalentdevice provided with suitable tripping means which may be operated bythe diaphragm and which may be placed under tension or otherwise havepower stored in it by the motor itself when operated,'the operation ofthe tripping device by the diaphragm when the pressure in thecombustion-chamber varies releasing the spring, and so causing thelatter to operate the motorcontroller. A spring provides ample power forthis purpose, and the work required to release it by the operation of asuitable tripper is very slight and is well within the range of powerobtainable from a diaphragm or other pressure-operated controllingdevice of convenient size.

The objects of my invention are therefore to render damper-operatingapparatus of the class described more certain in operation and reliableand also to improve the construction of such apparatus and to render thesame simple, compact, durable, and inexpensive as possible.

My invention consists in the operation of the motor-controllers ofdamper-operating apparatus of the class described by an actuating deviceinterposed between the motorcontroller and the primary actuating deviceordiaphragm of the apparatus; and itconsists also in the many novelfeatures of combination, construction, and arrangement of the parts bywhich the above-mentioned objects are accomplished.

In the accompanying drawings, which illustrate two embodiments of myinvention, Figure 1 is a front elevation of one form of damper-operatingapparatus embodied in my invention, the diaphragm-chamber beingsectioned. Fig. 2 is a transverse section of the apparatus shown in Fig.1 through the motor-cylinder and the regulating-valve of the motor. Fig.3 is a detail side view of the tripping mechanism employed on a scalelarger than that of Fig. 1. Fig. 4 is a view showing the method ofconnecting the damper-operating apparatus to a furnace. Fig. 5 is a sideelevation of another form of apparatus embodying my invention. Fig. 6 isa front elevation of such second form of apparatus. Fig. 7 is a detailsection through the resetting-sleeve. Fig. 8 is a horizontal sectionshowing a top view of the principal portion of the mechanism of suchsecond form of apparatus, and Fig. 9 is a perspective view of plate 60.

ICC

IIC

Referring now to the drawings, and first to Figs. 1 to 4, inclusive, 1is the cylinder of a hydraulic motor, 2 the piston thereof, and 3 thepiston-rod. The piston-rod may be connected to the damper to be operatedby a chain or other connecting device 3. in Fig. 4.)

4 and 5 are pipes communicating with the interior of the cylinder 1above and below the piston, respectively.

6, Fig. 2, is a turn-plug valve regulating the admission of water to thecylinder 1 and the exhaust therefrom and is the controller of the motor.7 is a supply-pipe, and 8 an exhaust-pipe. The valve-casing 6 isprovided with separate inlet-passages 9 and lO'for each end of thecylinder. Itis also provided with exhaust-passages 11 and 12 for eachend of the cylinder. The valve-plug 6 is provided with portscorresponding to these passages, the ports being so arranged that whenthe entrance-passage for one end of the cylinder is open thecorresponding exhaust-passage and the entrance-passage for the other endof the cylinder are closed, the exhaust-passage at the other end of thecylinder being open. Pipe 5 is connected by branches 5 and 5 with itsentrance-passage l0 and exhaust-passage 12, respectively. Pipe 4 isconnected by branches 4 and 4" with its entrance-passage 9 andexhaust-passage 11, re spectively. Pipe 7 is connected to the twoadmission-passages 9 and 10 by branches 7 and 7", and the exhaust-pipe 8is connected to the two exhaust-passages 11 and 12 by branches 8 and 8,respectively.

13 is a flexible diaphragm dividing into two parts a chamber inclosed bytwo sections 14 and 14" of a diaphragm-casing. The upper section 14 isperforated in various places to permit free passage of atmospheric air.To the section 14 is connected a pipe 15, which (Shown may lead to thecombustion-chamber of the furnace. Any decrease in pressure below atmospheric pressure in the combustion-cham her will cause a depression ofthe diaphragm 13. The diaphragm is provided with a stem 16, which passesupward through one of the perforations in the section 14 of thediaphragm-casing and has secured to it at one end a spring 17, the otherend of the spring being connected to a cord or the like 17, passing overa pulley 18 and wound upon a small drum 17 connected to a spring-drum21, hereinafter mentioned. The spring 17 serves both to balance theweight of the stern and the diaphragm and through the winding up of itscord 17 upon the drum 17 to coinpensate for the difference in rangebetween those variations in pressure which cause the closing of thedamper and those variations in pressure which cause the opening of thedamper.

20 is the stem of the valve-plug 6". Upon this stem there is mountedloosely a drum 21, to which is attached a sprocket-chain 22, suspendedfrom a bracket 23, carried by the piston-rod 3. The sprocket-chainserves to rotate the drum in one direction when the piston 2 rises. Acoiled spring 24 also surrounds the stem 20 and is attached at one endto the drum 21 by a pin 25. At the other end it is attached to any fixedportion of the appara tus. This spring serves to rotate the drum 21.backward when the piston 3 descends, and for it may be substituted anyother device for producing reverse rotation of the drum, such as asecond drum, weight, and cord. An arm 26 is keyed to the stem 20 andcarries a locking-disk 27, having two shoulders with which pivotedtriggers 28 and 29 are adapted to engage. A spring 30 between thesetriggers tends to press them against the lockingdisk 27. A spiral spring31 is mounted upon the valve-stem 20, its ends being extended andcrossed, as shown particularly in Fig. 3. Between these extended ends isa pin 32, carried by the arm 26, and also another pin 33, carried by thedrum 21.

A rocker-arm 34 is pivoted to a suitable support 35 and is connected bya link 36 with the stem 16 of the diaphragm. It also carries atripper-cam 37, Fig. 3, adapted to trip the triggers 28,,and 29 atproper times.

The diaphragm-stem 16 is provided with two notches 38 and 39. To itsguidingbracket 19 is pivoted a tilting locking-lever 40, adapted toengage the rod 16 in said notches. A spring 41 tends to hold thelocking-lever 40 in either extreme position in which it may be placed.The motion of said lever is limited by a pin 42, workingin a slot inbracket 43. Upon the side of the drum 21 are two pins 44 and 45, adaptedto engagethe lower end of the locking-lever 40, which is broadened out,as indicated in dotted lines in Fig. 3 and as shown in Fig. 2.

\Vhen in use,the damper-operating apparatus above described iscustomarily mounted inproximity to the furnace the damper of which it isto operate, as shown in Fig. 4, its piston-rod being connected by a cordor chain 3 or other suitable connecting device to an arm or leverconnected to the damper, the pipe 15 connecting its diaphragm-chamberwith the combustion-chamber of the furnace. The particulardamper-operating apparatus indicated in Fig. 4 is that shown in Figs. 5and 6; but the apparatus of Figs. 1, 2, and 3 is mounted in the samemanner. In Fig. 4 the damper, there shown in dotted lines in its closedposition and indicated by refer an extent sufficient to cause theapparatus to commence to operate and to open the damper. Theadmission-passage 10 of the valve 6 is open, as is the exhaust-passage11, so that water may flow into the cylinder 1 at the bottom and flowtherefrom at the top, so as to cause the piston to rise. As the pistonrises it causes the drum 21 to rotate against the tension of the spring24, and the pin 33, carried by said drum, winds up the spring 31, thearm 26 and locking-disk 27 being prevented from rotating by the trigger28, so that while that end of spring 31 which is in contact with pin 33is free to move with said pin the other end of the spring is heldstationary by pin 32. The diaphragm-stem 16 is also looked againstupward movement by the locking-lever 40, and is held locked untilthrough the rotation of the drum 21 the spring 31 has acquiredsufiicient tension to turn the valve-plug 6", when the diaphragm rises.After the spring 31 has acquired sufficient tension the pin 44 on thedrum 21 encounters the lower end of the locking-lever 40 and moves it tothe left of Figs. 1 and 3, thus releasing the diaphragmstem 16. Thisoccurs just as the piston in the cylinder 1 reaches the upper limit ofits stroke. The parts remain in this position, the damper being open,until the vacuum in the combustion-chamber of the furnace fallsas, forinstance, when the furnace-door is opened. The spring 17 then lifts thediaphragm-rod 16 and the diaphragm, and in so doing rotates the arm 34and the tripper-cam 37, raising the trigger 28, and thus leaving thelocking-disk 27 and arm 26 free to be rotated by the spring 31. Thespring 31 immediately causes rotation of said arm and locking-disk, andtherefore of the Valve-stem 20, attached thereto, thus rotating thevalve-plug 6", closing the admission-passage 10 and the exhaustpassage11 and opening the admission-passage 9 and the exhaust-passage 12that isto say, shutting off the supply of water from the lower end of thecylinder and admitting Water to the upper end of the cylinder andclosing the exhaust-opening at the upper end of the cylinder and openingthe exhaust-opening at the lower end of the cylinder. The piston of thecylinder 1 is thus caused to descend, closing the damper, and as itdescends the drum 21 is caused to rotate in a backward direction by thespring 24, the pin 33 engaging that end of the spring 31 which it didnot engage formerly and winding up said spring, thev locking-disk 27being prevented from rotating by the trigger 29. As soon as thediaphragmstem 16 reaches the upper limit of its travel it is engaged inits notch 39 by locking-lever 40. The diaphragm-stem 16 is thusprevented from falling until the spring 31 has acquired sufficienttension to turn the valve-plug 6" again. After the spring has acquiredsuch tension the pin 45 on the drum 21 engages the locking-lever 40 andmoves it to the right, thus leaving the rod 16 free to descend, althoughas the weight of the rod and diaphragm is balanced by the spring 17 saidrod and diaphragm will not descend untilthe vacuum in thecombustion-chamber is restored. The release of the rod 16 occurs just asthe piston in the cylinder reaches the lower limit of its stroke.

Compensation for the difference in range between the variations inpressure which cause the opening of the damper and those which cause itsclosing is accomplished by means of the spring 17, cord 17, and drum17", as follows: When the piston is down and the damper closed and thefurnace-draft ata minimum, the spring 17 is at its lowest tension, whichis just sufficient to balance the diaphragm and its stem. When after theclosing of the furnace-door and the consequent depression of thediaphragm the piston rises and the damper opens, as the piston rises andwinds up spring 24 it also winds up cord 17 upon drum 17 therebyincreasing the tension of spring 17, and the strength of this spring issuch that when the piston has reached the top spring 17 will be undersufficient tension so that upon the opening of the furnace-door theslightest decrease in draft caused thereby will still be sufficient topermit spring 17 to raise the diaphragm against the pull yet remainingon the diaphragm.

To return to the description of the operation of the apparatus: When thedamper in the furnace-offtake is closed and the furnacedraft is at aminimum, the diaphragm being held upward by the spring 17, although, asabove explained, at such time the tension of the spring is at a minimum,if the furnacedoor be closed the draft will be reestablished partiallyand the damper will be drawn down, rotating the arm 34 and thetripper-cam 37. The trigger 29 is thereby tripped, and the spring 31rotates the valve-plug 6, so as to restore it to the position shown inFig. 2, water being thereby admitted into the lower end of the cylinderand exhausted from the upper end thereof, so that the piston in saidcylinder rises and opens the damper. The motion of the locking-disk islimited by stops 4:9 and 50. (The latter shown in dotted lines in Fig.3.)

Figs. 5 to. 9, inclusive, illustrate another form of damper-operatingapparatus embodying my invention,in which the controllingvalve-actuatingdevice comprises two springs, one of which is compressed during theupstroke of the piston, the other during the downstroke of the piston,suitable tripping mechanism operated by the diaphragm serving to releasesaid springs at the proper time. The compensating device consists of aweight opposing another weight which counterbalances the diaphragm andits stem, said compensating weight bearing down upon the diaphragm stemwhen the damper is closed, so that a comparatively slight pull upon thediaphragm will depress the same and cause the operation of the motor,while a resetting-sleeve 53.

voaase when the damper is open the compensating weight is lifted offfrom the stem of the diaphragm, so that a much greater pull upon saiddiaphragm is required to keep it depressed. In these figures, numeral 1indicates the hydraulic cylinder; 2, the piston; 3, the piston-rod; 6,the controlling-valve, and 14 the diaphragm-casing. The interior of thiscasing is not shown, as it and the diaphragm are in all essentialparticulars the same as the corresponding parts of the apparatus shownin Figs. 1, 2, and 3. The hydraulic motor is single-acting, the pistonbeing caused to descend by reason of its weight, additional weightsbeing placed, if necessary, upon a pan 51, carried by the piston-rod 3.A casing 52 incloses the valve-actuating mechanism and is provided withsliding bearings for A resetting-rod 54, telescoping within sleeve 53,is provided with a head 55, Fig. 7, adapted to engage the upper end ofsleeve 53 near the upper limit of the stroke of the piston and lift saidsleeve. Springs 56 and 57 surround the resettingsleeve 53, being locatedbetween abutments 58 and 59, rigidly secured to sleeve 53, and betweenthese springs is a plate 60, loosely mounted upon the resettingsleeve. Alink 61 connects plate with an arm 62, connected to thecontrolling-valve 6 of the mo tor. Two tripping-arms 63 and 64 arepivoted to stationaryportions of the casing 52 and are adapted to engagein turn with plate 60. When so engaged, the said plate will be preventedfrom moving, and upon the movement of the resetting-rod one of thesprings 56 or 57 will be compressed against the said plate and powerwill be stored in such spring to move the said plate and to operate thevalve upon the release of the said trippingarm. The tripping-arms areadapted to be released by means of a tripping-plate 65, pivotallysupported upon a stationary portion of the machine and connected to thediaphragmstem 16'. In Fig. 6 plate 60 is shown as locked by tripping-arm64, spring 56 being compressed. If with the parts in this position thediaphragm be depressed, the lower end of tripping-plate 65 will swingoutward,

pushing outward the arm 64 until the plate 60 is released, when saidplate will be pressed downward by the spring 56 and the valve 6 will bereversed, the tripping-arm 63 falling having a pin overlapping the plate65.

The resetting-sleeve 53 carries a lockingplate 71, in which are recesses72 and 73.

The tripping-plate 65 has two projections carrying friction-rollers 74and 75, adapted to coact with locking-plate 71. The manner of operationof this locking device will be made apparent in the description of theoperation of the apparatus.

In Figs. 5 and 6 the parts are shown in the positions corresponding to aclosed position of the furnace-damper and to an open position of thefurnace-door. The compensating, weight 68 is supported through its pin70 by the tripping-plate 65, and therefore is counterbalancing in ameasure the moment of the counterbalance-weight 67. It now thefurnace-door be closed, the diaphragm will be depressed and thetripping-plate 65 will be moved about its pivot, this being permitted bythe recess 72 in locking-plate 71, which recess friction-roller 74 willenter, and trippingplate 65 being thus rocked will press arm 64 out,thereby releasing plate 60, which is then pressed downward by spring 56,thus reversing the controlling-valve 6 of the motor and admitting waterinto the cylinder 1, so as to raise the piston. As the piston rises thefurnace-damper will open, and when the piston has neared the upper limitof its stroke the head 55 of resetting-rod 54 will encounter the upperend of resetting-sleeve 53 and, picking up the latter, will cause spring64 to be c0mpressed against plate 60, which plate is now held locked bytripping-arm 63, now in position over plate 60. Resetting-sleeve 53 inits upward movement carries with it the lockingplate 71, and as soon asrecess 72 in said plate is no longer opposite roller 74 thetrippingplate 65 is locked against motion in either direction, andtherefore premature rise of the diaphragm, due, for instance, to openingof the furnace-door before spring 56 has acquired sufficient tension tooperate valve 6, can produce no immediate effect. When the piston hasreached the upper limit of its stroke and the damper is Wide open,aprojection 76 on locking-plate 71 will have picked uprod 69, carryingcompensating weight 68, so as to relieve the counterbalance-weight 67 ofthe counteracting influence of said compensating weight. In thisposition of the parts roller of locking-plate 65 is opposite recess 73,so that if the diaphragm be permitted to rise through decrease of thesuction upon it the locking-plate 71 will permit the necessary movementof the tripping-plate 65, the tripping-arm 63 will be moved out, theplate 60 will be moved upward by spring 57, and the valve 6 will bereversed, so as to open cylinder 1' to exhaust, thereby permitting thepiston to descend by its own weight and close the furnace-damper, and atthe same time the tripping-arm 64 will swing underneath plate 66, sothat upon the descent of the resetting-sleeve 53, consequent upon thedescent of the piston, spring 56 will be compressed, and during thedownward movement of the resetting-sleeve the tripping-plate 60 and thediaphragm will be held locked until spring 56 shall have acquired fulltension. As the locking-plate 71 descends the weight 68 is again causedto act through its pin 70 in opposition to the counterbalance-weight 67,thereby compensating for the difference in range between the variationsin pressure which must suffice to close the damper and those which mustsuffice to open it.

It is obvious that both forms of apparatus above described are capableof many modifications and changes in construction, and I do not limitmyself to the particular constructions herein illustrated and described.

Having thus completely described my in vention, what I claim, and desireto secure by Letters Patent, is-

1. In an apparatus for operating dampers in furnace-offtakes, thecombination, with a motor for moving such dampers and a motorcontroller,of an actuating device for operating said motor-controller, a primarycontrolling device operated by variations in pressure in thecombustion-chamber, means operated by said primary controlling devicecontrolling the operation of said actuating device, which actuatingdevice derives its power from a source independent of the primarycontrolling device, and a compensating device for compensating for thedii'ference in range between thosevariations in pressure which operatethe apparatus to close the damper and those variations in pressure Whichoperate to open the damper.

2. In an apparatus for operating dampers in furnace-offtakes, thecombination, with a fluid-pressure motor for moving such dampers, and acontrolling-valve for such motor,-

of an actuating device for operating said valve, a primary controllingdevice operated by variations in pressure in the combustionchamber,means operated by said primary controlling device controlling theoperation of said actuating device, which actuating de vice derives itspower from a source independent of the primary controlling device, and acompensating device for compensating for the difference in range betweenthose variations in pressure which operate the apparatus to close thedamper and those variations which operate to open the damper.

3. In an apparatus for operating dampers in furnace-offtakes, thecombination, with a motor for moving such dampers, and amotorcontroller, of an energy-storing actuating device arranged tooperate said motor-controller when released, means operated by the motorfor storing up energy in said actuating device, a primary controllingdevice operated by variations inpressure in the combustion chamber,means operated by the said primary controlling device, adapted torelease the actuating device, and a compensating device, forcompensating for the difference in range between the variations inpressure which operate the apparatus to close the damper and thosevariations which operate to open the damper.

ate to open the damper.

5. In an apparatus for operating dampers in furnace-offtakes, thecombination, with a motor for moving such dampers and a motorcontroller,of a primary controlling device operated by variations in pressure inthe combustion-chamber, an energy-storing actuating device for operatingthe motor-controller,

mechanically connected with and controlled I by said primary controllingdevice, but deriving its powerfrom an independentsource, and acompensating device for compensating for the difference in range betweenthe variations in pressure which operate the apparat us to close thedamper and those variations which operate to open the damper.

6. In an apparatus for operating dampers in furnace-offtakes, thecombination, with a motor for moving such dampers and a motorcontroller,of a primary controlling device operated by variations in pressure inthe combustion-chamber, an energy-storing actuating device for operatingthe motor-controller, in which power is stored for such purpose by themotor in its operation, and which is mechanically connected with andcontrolled by said primary controlling device, and a compensating devicefor compensating for the difference in range between the variations inpressure which operate the apparatus to close the damper and thosevariations which operate to open the damper.

'7. In an apparatus for operating dampers in furnace-offtakes, thecombination, with a motor for moving such dampers and a motorcontroller,of a primary controlling device operated by variations in pressure inthe combustion-chamber, an energy-storing actuating device for operatingthe motor-controller, comprising a power-storing device, means operatedby the motor in its operation for stor ing power therein, and a trippingmechanism for releasing said power-storing device, such trippingmechanism being arranged to be operated by the primary controllingdevice; and a compensating device for compensating for the difference inrange between the variations in pressure which operate the apparatus toclose the dampers and those variations which operate to open thedampers.-

8. In an apparatus for operating dampers in furnace-offtakes, thecombination, with a motor, a motor-controller, an energy-storingactuating device for operating the motor controller, adapted to bereleased by a suitable tripping device, and means for storing up energyin said actuating device, of a primary controlling device adapted to beoperated by change of conditions within the furnace and to release saidactuating device, and provided with an antomatically-operated locking device which prevents changes of conditions within the furnace fromcausing the operation of said controlling device, when once theactuating device has been released by said controlling device, untilsufficient energy has been stored in said actuating device to againoperate the motor-controller.

9. In an apparatus for operating dampers in furnaceofftakes, thecombination, with a motor, a motor-controller, an energy-storingactuating device for operating the motor-controller, adapted to bereleased by a suitable tripping device, and means for storing up energyin said actuating device, of a primary controlling device adapted to beoperated by change of conditions within the furnace and to release saidactuating device, provided with an automatically-operated locking devicewhich prevents changes of conditions within the furnace from causing theoperation of said controlling device, When once the actuating device hasbeen released by said controlling device, until sufficient energy hasbeen stored in said actuating device to again operate themotor-controller, and a compensating device for compensating for thedifference in range between the variations in pressure which operate theapparatus to close the damper and those variations which operate to openthe damper.

10. The combination, with a motor, a motor-controller, an energy-storingactuating device for operating the motor-controller,adapted to bereleased by a suitable controlling device, and means for storing upenergy in said actuating device, of a controlling device provided with alock for preventing its operation at intervals, said controlling devicebeing adapted to release said actuating device, and means for operatingthe look so as to prevent the operation of said controlling device whileenergy is being stored in the actuating device.-

11. The combination, with a reciprocating motor, a motor-controller, anenergy-storing actuating device for operating the motor-controller,adapted to be released by a suitable controlling device, and means forstoring up energy in said actuating device, of a controlling deviceprovided With an automaticallyoperated lock for preventing its operationat intervals, said controlling device being adapted to release saidactuating device,and means, operated by the motor, for operating thelockso as to prevent the operation of said controlling device while themotor is operating.

12. In a damper-operating apparatus, the combination with a motor and amotor-controller, of a spring, an arm connected with themotor-controller and engaging one end or the other of said springaccording to the direction in which the motor-controller is to beoperated, tripping devices adapted to hold said arm stationary while thespring is being Wound up, a spring -winding member mechanicallyconnected with the motor and arranged to wind the spring in onedirection or the other according to the direction in which themotor-controller is to be operated, and means for operating the saidtripping devices to release said arm.

13. In a damper-operating apparatus, the combination,with a motor,a1notor-controller, a spring,an arm connected with the motor-c011-troller and revolubly mounted and arranged to engage one end of thespring or the other, according to the direction in which the spring isto be wound, and tripping-triggers, one adapted to hold said arm againstmotion in one direction and the other to hold it against motion in theopposite direction, of a springwinding member mechanically connectedwith themotor and adapt-edto wind said spring in one direction or theother according to the direction in which the mot0r-controller is to beoperated, and a cam for operating said triggers and releasing said arm.

14. In a damper-operating apparatus, the combination,with a motor, amotor-controller, an energy-storing controlling device for operating themotor-controller, tripping devices controlling the operation of saidenergy-storing device, and means operated by the motor for storingenergy in such energy-storing device as the motor operates, of anactuating member for actuating said tripping devices, having notches, alocking-pawl adapted to engage said notches and hold said actuatingmember stationary while energy is being stored, and means for releasingsaid actuating member when full power has been stored.

In testimony whereof I affix my signature in the presence of twowitnesses.

HENRY B. P. WR'ENN.

\Vitnesses:

H. M. MARBLE, A. H. PERLES.

